We've been offered a boxer pup from dam - buffy slayer and sire - mooresax brazilian blend. How do we find out more information on the parents/grandparents etc without asking the owner?

You can ask the KC but if you are having sufficient doubts not to want to ask the owner you should be persuing this litter :) Your puppies breeder should be someone you trust and comunicate well with:)

when you get your puppy you can get a 5 generation pedigree printed from the kennel club - but usually a breeder should have that available for you to look at before you purchase the puppy i know i do, then the new people can see any health cks done and who's in the pedigree.

The dam doesn't have an affix so that's difficult to check.  The sire's name doesn't come up on any search.  Hopefully someone who knows boxer lines maybe able to help, but it doesn't seem promising that they are from known breeding.

Does sound a bit like they have been bred by someone who thought it may be nice for their bitch to have a litter and probably used the nearest available male. If it were me I would ask if the pups are to be registered, had the breeder bred before, have the dam and sire had the health tests particularly the heart & hips. As you have asked on here I feel you are not totally happy with this litter or this breeder so perhaps you should look elsewhere, as far as I know it is not too difficult to find well bred examples of the breed.

Ive been in touch with the breeders and the parents havent been heart tested and the pups wont have had first injections as they will be letting them go at 6 and a half weeks , so as you can imagine we're steering clear and looking else where!!

Well done.  I think you've made the right decision!!! :D

If only all people took the time to do what sweety did and check the history of the dogs out and also ask the breeders the IMPORTANT questions! Good on you sweety!

Sorry you had to make the decision you did but sure you wont regret it. I would not worry about the 1st injection but expect the health tests to be done and want to know that the sire was chosen with care and not just because he was convenient.